168 WATCHED BY WILD ANIMALS 
caribou are experts in taking care of themselves 
during long winters of deep snows. They 
select a yard which offers the maximum food 
supply and other winter opportunities. 
One snowy winter I visited a number of elk 
that were yarding. High peaks rose snowy and 
treeless above the home in the forest. The 
ragged-edged yard was about half a mile long 
and a quarter of a mile wide. About one half 
the yard was a swamp covered with birch and 
willow and a scattering of fir. The remainder 
was a combination of open spaces, aspen groves, 
and a thick growth of spruce. 
Constant trampling compressed the snow and 
enabled the elk readily to move about. Out- 
side the yard they would have bogged in deep 
snow. In the swamp the elk reached the moss, 
weeds, and other growths. But toward spring 
the grass and weeds had either been eaten or 
were buried beneath icy snow. The elk then 
ate aspen twigs and the tops and limbs and 
bark of birch and willow. 
Ease of movement in this area enabled the 
elk to keep enemies at bay. Several times I 
saw from tracks that lion had entered this self- 
made wild life reservation, and on two occasions 
a number of wolves invaded it. But each time 
the elk had bunched in a pocket of a trampled 
space and effectively fought off the wolves, 
